ATTenergy 12.8V 40Ah LiFePO4 Battery Pack with PCB Built with 8 pieces 3.2V 20Ah LiFePO4 (Lithium Iron Phosphate) Rechargeable Battery More capacity per gram, meaning longer duration between charges. Almost no ''self discharge'', so it is always ready to go even weeks after charging. Faster charge time Ideal pack to replace lead acid 12V battery.SpecificationsVoltage12.8V Capacity40000mah Connectorno connector, bare leads Dimensionapprox. 139mm x 160mm x 121mm Weightapprox. 5Kg (11 lbs)CautionThis pack is LiFePO4 chemistry. Only charge them on quality chargers which have a dedicated charge routine for LifePO4 cells. NEVER attempt to charge damaged packs.Read all cautions on product packaging before using these packs.